document.addEventListener('DOMContentLoaded', () => {
    // DOM Elements
    const videoGrid = document.getElementById('videoGrid');
    const searchInput = document.getElementById('searchInput');
    const clearSearchBtn = document.getElementById('clearSearch');
    const videoModal = document.getElementById('videoModal');
    const videoPlayer = document.getElementById('videoPlayer');
    const modalVideoTitle = document.getElementById('modalVideoTitle');
    const closeModal = document.getElementById('closeModal');
    const loadingIndicator = document.getElementById('loadingIndicator');
    const errorMessage = document.getElementById('errorMessage');
    const retryBtn = document.getElementById('retryBtn');
    const gridViewBtn = document.getElementById('gridViewBtn');
    const listViewBtn = document.getElementById('listViewBtn');
    const pagination = document.getElementById('pagination');
    const visibleCount = document.getElementById('visibleCount');
    const totalCount = document.getElementById('totalCount');

    // State
    let videos = [];
    let filteredVideos = [];
    let currentPage = 1;
    let videosPerPage = 12;
    let currentPlayer = null;
    let viewMode = 'grid';
    let lastTapTime = 0;
    let lastDoubleTapX = 0;
    let doubleTapThreshold = 10; // px tolerance for tap position

    // Initialize the app
    init();

    function init() {
        fetchVideoData();
        setupEventListeners();
    }

    // Fetch video data from JSON
    async function fetchVideoData() {
        try {
            loadingIndicator.style.display = 'flex';
            errorMessage.style.display = 'none';
            videoGrid.innerHTML = '';

            const response = await fetch('database.json');
            if (!response.ok) {
                throw new Error(`Failed to load database.json: ${response.status}`);
            }

            const data = await response.json();
            
            // Check if data has the expected structure
            if (!data.videos || !Array.isArray(data.videos)) {
                throw new Error('Invalid database format: missing "videos" array');
            }

            // Filter out invalid entries
            videos = data.videos.filter(video => {
                if (!video.title || !video.url) {
                    console.warn('Invalid video entry:', video);
                    return false;
                }
                return true;
            });

            filteredVideos = [...videos];
            updateVideoCount();
            renderPagination();
            renderVideos();

            showToast('Videos loaded successfully!', 'success');
        } catch (error) {
            console.error('Error loading videos:', error);
            loadingIndicator.style.display = 'none';
            errorMessage.style.display = 'flex';
        }
    }

    // Set up event listeners
    function setupEventListeners() {
        // Search functionality
        searchInput.addEventListener('input', handleSearch);
        clearSearchBtn.addEventListener('click', clearSearch);

        // Modal controls
        closeModal.addEventListener('click', closeVideoModal);

        // Retry button
        retryBtn.addEventListener('click', fetchVideoData);

        // View toggle
        gridViewBtn.addEventListener('click', () => setViewMode('grid'));
        listViewBtn.addEventListener('click', () => setViewMode('list'));

        // Handle clicks outside the modal to close it
        window.addEventListener('click', (e) => {
            if (e.target === videoModal) {
                closeVideoModal();
            }
        });

        // Keyboard controls for modal
        window.addEventListener('keydown', (e) => {
            if (videoModal.style.display === 'block') {
                if (e.key === 'Escape') {
                    closeVideoModal();
                }
            }
        });
    }

    // Handle search input
    function handleSearch() {
        const searchTerm = searchInput.value.toLowerCase().trim();
        clearSearchBtn.style.display = searchTerm ? 'block' : 'none';
        
        if (searchTerm === '') {
            filteredVideos = [...videos];
        } else {
            filteredVideos = videos.filter(video => 
                video.title.toLowerCase().includes(searchTerm)
            );
        }
        
        currentPage = 1;
        updateVideoCount();
        renderPagination();
        renderVideos();
    }

    // Clear search
    function clearSearch() {
        searchInput.value = '';
        clearSearchBtn.style.display = 'none';
        filteredVideos = [...videos];
        currentPage = 1;
        updateVideoCount();
        renderPagination();
        renderVideos();
    }

    // Update video count display
    function updateVideoCount() {
        const start = (currentPage - 1) * videosPerPage;
        const end = Math.min(start + videosPerPage, filteredVideos.length);
        const count = Math.min(videosPerPage, filteredVideos.length - start);
        
        visibleCount.textContent = count > 0 ? end - start : 0;
        totalCount.textContent = filteredVideos.length;
    }

    // Set view mode (grid or list)
    function setViewMode(mode) {
        viewMode = mode;
        
        // Update active button
        gridViewBtn.classList.toggle('active', mode === 'grid');
        listViewBtn.classList.toggle('active', mode === 'list');
        
        // Update grid class
        videoGrid.classList.toggle('list-view', mode === 'list');
        
        // Re-render to apply changes
        renderVideos();
    }

    // Render videos in grid
    function renderVideos() {
        loadingIndicator.style.display = 'none';
        videoGrid.innerHTML = '';
        
        if (filteredVideos.length === 0) {
            videoGrid.innerHTML = `
                <div class="error-container" style="grid-column: 1 / -1;">
                    <i class="fas fa-search"></i>
                    <p>No videos found matching your search.</p>
                </div>
            `;
            return;
        }
        
        // Calculate pagination
        const start = (currentPage - 1) * videosPerPage;
        const end = Math.min(start + videosPerPage, filteredVideos.length);
        const currentPageVideos = filteredVideos.slice(start, end);
        
        // Create video cards
        currentPageVideos.forEach((video, index) => {
            const videoCard = document.createElement('div');
            videoCard.className = `video-card ${viewMode === 'list' ? 'list-view' : ''}`;
            
            // Determine if URL is from Hugging Face
            const isHuggingFaceUrl = video.url.includes('huggingface.co');
            
            // For HF URLs, append download=true if not already present
            let videoUrl = video.url;
            if (isHuggingFaceUrl && !videoUrl.includes('download=true')) {
                videoUrl = videoUrl.includes('?') ? 
                    `${videoUrl}&download=true` : 
                    `${videoUrl}?download=true`;
            }
            
            videoCard.innerHTML = `
                <div class="video-thumbnail">
                    <div class="thumbnail-placeholder">
                        <i class="fas fa-film fa-2x"></i>
                    </div>
                    <div class="play-icon">
                        <i class="fas fa-play fa-lg"></i>
                    </div>
                </div>
                <div class="video-info">
                    <h3 class="video-title">${video.title}</h3>
                </div>
            `;
            
            videoCard.addEventListener('click', () => {
                playVideo(video);
            });
            
            videoGrid.appendChild(videoCard);
        });
    }

    // Render pagination controls
    function renderPagination() {
        pagination.innerHTML = '';
        
        if (filteredVideos.length <= videosPerPage) {
            return; // No pagination needed
        }
        
        const totalPages = Math.ceil(filteredVideos.length / videosPerPage);
        
        // Previous button
        const prevBtn = document.createElement('button');
        prevBtn.className = `page-btn ${currentPage === 1 ? 'disabled' : ''}`;
        prevBtn.innerHTML = '<i class="fas fa-chevron-left"></i>';
        prevBtn.disabled = currentPage === 1;
        prevBtn.addEventListener('click', () => {
            if (currentPage > 1) {
                goToPage(currentPage - 1);
            }
        });
        pagination.appendChild(prevBtn);
        
        // Page numbers with ellipsis
        const renderPageButton = (pageNum) => {
            const pageBtn = document.createElement('button');
            pageBtn.className = `page-btn ${currentPage === pageNum ? 'active' : ''}`;
            pageBtn.textContent = pageNum;
            pageBtn.addEventListener('click', () => goToPage(pageNum));
            pagination.appendChild(pageBtn);
        };
        
        // Determine visible page range
        const delta = 2; // Number of pages to show on each side of current
        const range = [];
        const rangeWithDots = [];
        let l;
        
        range.push(1);
        
        for (let i = currentPage - delta; i <= currentPage + delta; i++) {
            if (i > 1 && i < totalPages) {
                range.push(i);
            }
        }
        
        range.push(totalPages);
        
        for (let i of range) {
            if (l) {
                if (i - l === 2) {
                    rangeWithDots.push(l + 1);
                } else if (i - l !== 1) {
                    rangeWithDots.push('...');
                }
            }
            rangeWithDots.push(i);
            l = i;
        }
        
        rangeWithDots.forEach(item => {
            if (item === '...') {
                const ellipsis = document.createElement('span');
                ellipsis.className = 'page-btn disabled';
                ellipsis.textContent = '...';
                pagination.appendChild(ellipsis);
            } else {
                renderPageButton(item);
            }
        });
        
        // Next button
        const nextBtn = document.createElement('button');
        nextBtn.className = `page-btn ${currentPage === totalPages ? 'disabled' : ''}`;
        nextBtn.innerHTML = '<i class="fas fa-chevron-right"></i>';
        nextBtn.disabled = currentPage === totalPages;
        nextBtn.addEventListener('click', () => {
            if (currentPage < totalPages) {
                goToPage(currentPage + 1);
            }
        });
        pagination.appendChild(nextBtn);
    }

    // Navigate to a specific page
    function goToPage(pageNum) {
        currentPage = pageNum;
        updateVideoCount();
        renderPagination();
        renderVideos();
        
        // Scroll to top of video grid
        videoGrid.scrollIntoView({ behavior: 'smooth' });
    }

    // Play video in modal
    function playVideo(video) {
        // Clean up any existing player
        cleanupPlayer();
        
        // Update modal title
        modalVideoTitle.textContent = video.title;
        
        // Determine if URL is from Hugging Face
        const isHuggingFaceUrl = video.url.includes('huggingface.co');
        
        // For HF URLs, append download=true if not already present
        let videoUrl = video.url;
        if (isHuggingFaceUrl && !videoUrl.includes('download=true')) {
            videoUrl = videoUrl.includes('?') ? 
                `${videoUrl}&download=true` : 
                `${videoUrl}?download=true`;
        }
        
        // Set up video player
        videoPlayer.src = videoUrl;
        
        // Initialize Plyr
        currentPlayer = new Plyr(videoPlayer, {
            controls: [
                'play-large', 'play', 'progress', 'current-time', 'mute', 
                'volume', 'captions', 'settings', 'pip', 'airplay', 'fullscreen'
            ],
            keyboard: { focused: true, global: false },
            tooltips: { controls: true, seek: true },
            captions: { active: true, language: 'auto', update: true }
        });
        
        // Set up double-tap controls for mobile
        setupDoubleTapControls();
        
        // Show modal
        videoModal.style.display = 'block';
        document.body.style.overflow = 'hidden'; // Prevent scrolling while modal is open
        
        // Play the video (with error handling)
        try {
            currentPlayer.play().catch(error => {
                console.warn('Failed to autoplay video:', error);
                
                // Check if it's a format issue
                const fileExtension = videoUrl.split('.').pop().toLowerCase();
                if (fileExtension === 'mkv') {
                    showToast('MKV format may not be fully supported in your browser.', 'warning');
                }
            });
        } catch (error) {
            console.error('Error playing video:', error);
            showToast('Error playing video. Please try again.', 'error');
        }
    }

    // Set up double-tap controls for mobile
    function setupDoubleTapControls() {
        const playerElement = videoPlayer.closest('.player-container');
        
        const handleTap = (e) => {
            const now = Date.now();
            const tapX = e.touches ? e.touches[0].clientX : e.clientX;
            const playerWidth = playerElement.offsetWidth;
            const tapPosition = tapX / playerWidth; // 0 to 1 position
            
            if (now - lastTapTime < 300 && Math.abs(tapX - lastDoubleTapX) < doubleTapThreshold) {
                // Double tap detected
                e.preventDefault();
                
                if (tapPosition < 0.3) {
                    // Double tap on left side - rewind
                    currentPlayer.rewind(10);
                    showControlFeedback('left', 'Rewind 10s');
                } else if (tapPosition > 0.7) {
                    // Double tap on right side - forward
                    currentPlayer.forward(10);
                    showControlFeedback('right', 'Forward 10s');
                } else {
                    // Double tap in center - play/pause
                    if (currentPlayer.playing) {
                        currentPlayer.pause();
                    } else {
                        currentPlayer.play();
                    }
                }
            }
            
            lastTapTime = now;
            lastDoubleTapX = tapX;
        };
        
        // Add touch event listeners
        playerElement.addEventListener('touchstart', handleTap);
        
        // Store for cleanup
        playerElement.handleTapFunc = handleTap;
    }

    // Visual feedback for touch controls
    function showControlFeedback(position, text) {
        const playerElement = videoPlayer.closest('.player-container');
        
        // Create a feedback element
        const feedback = document.createElement('div');
        feedback.className = `tap-feedback ${position}`;
        feedback.innerHTML = `
            <div class="feedback-icon">
                <i class="fas fa-${position === 'left' ? 'backward' : position === 'right' ? 'forward' : 'play'}"></i>
            </div>
            <div class="feedback-text">${text}</div>
        `;
        
        // Style it
        feedback.style.position = 'absolute';
        feedback.style.top = '50%';
        feedback.style.transform = 'translateY(-50%)';
        feedback.style.color = 'white';
        feedback.style.backgroundColor = 'rgba(0,0,0,0.6)';
        feedback.style.padding = '15px';
        feedback.style.borderRadius = '50%';
        feedback.style.display = 'flex';
        feedback.style.flexDirection = 'column';
        feedback.style.alignItems = 'center';
        feedback.style.opacity = '0';
        feedback.style.animation = 'fadeInOut 1s ease-in-out';
        
        if (position === 'left') {
            feedback.style.left = '15%';
        } else if (position === 'right') {
            feedback.style.right = '15%';
        } else {
            feedback.style.left = '50%';
            feedback.style.transform = 'translate(-50%, -50%)';
        }
        
        // Add animation
        const keyframes = `
            @keyframes fadeInOut {
                0% { opacity: 0; }
                20% { opacity: 1; }
                80% { opacity: 1; }
                100% { opacity: 0; }
            }
        `;
        
        const style = document.createElement('style');
        style.textContent = keyframes;
        document.head.appendChild(style);
        
        // Add to player
        playerElement.appendChild(feedback);
        
        // Remove after animation
        setTimeout(() => {
            feedback.remove();
            style.remove();
        }, 1000);
    }

    // Close video modal and clean up player
    function closeVideoModal() {
        // Clean up player first
        cleanupPlayer();
        
        // Hide modal
        videoModal.style.display = 'none';
        document.body.style.overflow = ''; // Restore scrolling
    }

    // Clean up video player
    function cleanupPlayer() {
        // If a player instance exists, destroy it
        if (currentPlayer) {
            // Make sure video is paused
            try {
                currentPlayer.pause();
            } catch (e) {
                console.warn('Error pausing player:', e);
            }
            
            // Try-catch to handle potential Plyr errors
            try {
                currentPlayer.destroy();
            } catch (e) {
                console.warn('Error destroying Plyr instance:', e);
            }
            
            currentPlayer = null;
        }
        
        // Directly manipulate the video element as a failsafe
        videoPlayer.pause();
        videoPlayer.removeAttribute('src');
        videoPlayer.load(); // Important: this resets the video element
        
        // Remove any event listeners from the player container
        const playerElement = videoPlayer.closest('.player-container');
        if (playerElement && playerElement.handleTapFunc) {
            playerElement.removeEventListener('touchstart', playerElement.handleTapFunc);
            delete playerElement.handleTapFunc;
        }
        
        // Clear any existing feedback elements
        const feedbacks = document.querySelectorAll('.tap-feedback');
        feedbacks.forEach(el => el.remove());
    }

    // Show toast message
    function showToast(message, type = 'info') {
        const toastContainer = document.getElementById('toastContainer');
        
        const toast = document.createElement('div');
        toast.className = `toast ${type}`;
        toast.textContent = message;
        
        toastContainer.appendChild(toast);
        
        // Remove toast after animation completes
        setTimeout(() => {
            toast.remove();
        }, 3000);
    }
});